kafka: _MINIO_KAFKA_DEBUG to enable sarama debug messages (#19849)

internal/logger/target/kafka/kafka.go

@@ -24,6 +24,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"log"
 	"os"
 	"path/filepath"
 	"sync"
@@ -234,6 +235,10 @@ func (h *Target) send(entry interface{}) error {
 
 // Init initialize kafka target
 func (h *Target) init() error {
+	if os.Getenv("_MINIO_KAFKA_DEBUG") != "" {
+		sarama.DebugLogger = log.Default()
+	}
+
 	sconfig := sarama.NewConfig()
 	if h.kconfig.Version != "" {
 		kafkaVersion, err := sarama.ParseKafkaVersion(h.kconfig.Version)